In a nod to the growing senior population of Greenwich, which endured a decade of wrangling over the financing and scope of the project, the town finally broke ground Thursday on a $25.6 million renovation at the Nathaniel Witherell nursing home with a hand from Gov. Dannel P. Malloy.

Malloy scooped a small pile of dirt with a ceremonial shovel outside the town-owned and operated facility in unison with First Selectman Peter Tesei and the nursing home's brass, who donned hard hats for the groundbreaking.

The languishing project at the 202-bed facility on Parsonage Road took on a personal attachment for Malloy, who visited with Mary Klein, 91, a nursing home resident who was friends with the governor's late mother, Agnes Malloy.

Klein presented Malloy, who was mayor of neighboring Stamford from 1995 to 2009, with homemade brownies that the governor had shown a sweet tooth for through the years.

"People don't choose to get old. They grow into it," Malloy told a mix of residents, nursing home staff and elected officials. "Like people, facilities, too, get old."

Under what is known as Project Renew, the number of private bedrooms will increase from 26 to 60; double-bed rooms from 136 to 142. At the same time, 40 less-popular four-bed rooms will be eliminated during the renovation.

Other highlights of the renovation include the installation of a sprinkler system in the nursing home's administration building; new boilers; upgrades to backup power generators, heating and hot water systems; improvements to bathrooms and nursing stations; and expansion of the rehabilitation space.

The renovation is scheduled to finish in 2014, according to the nursing home, which has estimated its current occupancy rate of 93 percent would slip to 85 percent during construction.

"There's a huge number of people that have a stake in this claim," said Allen Brown, the nursing home's executive director.

Brown worked under Malloy when he was Stamford's mayor as director of the city-owned Smith House nursing home.

Town officials credited Malloy with helping the Nathaniel Witherell to obtain its certificate of need for the project from the state Department of Social Services and with helping to increase the Medicaid reimbursement rates for the construction.

The nursing home had been receiving $243.42 per day for each Medicaid patient, far below the $300-per-patient daily cost to provide care for such patients. The state agreed to raise the per diem to $257.16, which could help defray $12 million of the project's $25.6 million total cost when compounded over 20 years.

"If there's any institution that epitomizes the heart of our town, it's the Witherell," said Tesei, the town's chief elected official.

Tesei's grandmother spent the final six years of her life in what is now known as the Camelot unit, a 38-bed section devoted to dementia patients.

The nursing home's administration building dates back to 1933. The tower building was put up in 1971.

Previously, fiscal stewards scrapped a 2002 plan to raze the nursing home and build anew, which came with a $45.2 million price tag.

In December 2011, the Representative Town Meeting approved a $20.2 million bonding measure for a scaled-down renovation after significant lobbying.

The renovation's proponents cited a needs assessment by the United Way of Greenwich showing 17 percent of the town's residents are over 65, which is above the state's 14 percent average. The median age in Greenwich is 43 years, four years older than the state average, according to the same survey.

Office holders on both sides of the political aisle showed their solidarity at the ground-breaking.

"An awful lot of people have done a tremendous amount of work," said U.S. Rep. Jim Himes, D-4th District, who lives in Cos Cob.